1. Field of the Invention
The present invention relates to an apparatus for disassembling mating taper connections, and, more particularly to an apparatus for disassembling Morse taper connections in modular prosthetic implants.
2. Description of the Related Art
Mating taper connections can be used for temporarily securing one item to another. One such taper connection is a Morse taper connection. Generally, a Morse taper is defined as a taper connection having a taper surface making an angle of about 2 to 12 degrees relative to the longitudinal axis of the component. Morse taper connections can be made between interpenetrating parts, with, e.g., a first of the parts having a tapered bore, and a second of the parts having a frustoconical shape for securement in the tapered bore of the first part. The tapered bore and the frustoconical shape can have slightly different sizes or taper angles to facilitate securement of the parts via the mating taper connection as described below. To assemble mating taper connections, including Morse taper connections, items having a mating taper structure are interference fit one to the other to cause cointegration or locking of the items. In some cases the cointegration results in material transfer across the zone of contact, i.e., cold welds.
For example, modular femoral implants utilize a Morse taper to secure the proximal body to the distal stem. One such modular femoral implant is the modular femoral implant utilized in the ZMR™ Hip System produced by Zimmer, Inc of Warsaw Indiana. In modular femoral implants, the distal stem generally includes a frustoconical proximal end comprising the male portion of the locking taper, with the longitudinal bore of the proximal body including a mating female taper formed in the distal portion of the longitudinal bore of the proximal body.
A locking taper connection makes a strong connection between two components making disassembly of the components difficult. The present invention is directed to an apparatus for facilitating disassembly of components secured together via a mating taper connection.